a=float(input("输入需要的米数"))
b=a/3
c=int(b)
if b:
    print(str(c+1)+"根")
else:
    print(int(c)+"根")


# A=input("数字")
# B=input("数字")
# C=input("数字")
# a=int(A)
# b=int(B)
# c=int(C)
#
# if a>=b and b>=c:
#     print(c,b,a)
# elif a>=c and c>=b:
#     print(b,c,a)
# elif b>=a and a>=c:
#     print(c,a,b)
# elif b>=c and c>=a:
#     print(a,c,b)
#
# if a-b>0:
#     if b-c>0:
#         print(C,B,A)
#     else:
#         if a-c>0:
#             print(B,C,A)
#         else:
#             print(B,A,C)
# else:
#     if a-c>0:
#         print(C,A,B)
#     else:
#         if b-c>0:
#           print(A,C,B)
#         else:
#             print(A,B,C)
#
#
#
#
# # a=int(input("购物金额"))
# # b=int(input("换购活动"))
# # if b==0:
# #     print("实际支付",a)
# # elif b==1 and a>50:
# #     a+=1
# #     print("实际支付",a)
# #     print("500毫升可乐")
# # elif b==2 and a>100:
# #     a=a+2
# #     print("实际支付",a)
# #     print("1000毫升果汁")
# # elif b==3 and a>100:
# #     print("实际支付",(a+4))
# #     print("炫迈口香糖一瓶")
# # elif b==4 and a>200:
# #     print("实际支付",(a+38))